Nanowire Bundles Research Articles

Ultrathin, High-Aspect-Ratio Bismuth Sulfohalide Nanowire Bundles for Solution-Processed Flexible Photodetectors.

In this study, a novel synthesis of ultrathin, highly uniform colloidal bismuth sulfohalide (BiSX where X = Cl, Br, I) nanowires (NWs) and NW bundles (NBs) for room-temperature and solution-processed flexible photodetectors are presented. High-aspect-ratio bismuth sulfobromide (BiSBr) NWs are synthesized via a heat-up method using bismuth bromide and elemental S as precursors and 1-dodecanethiol as a solvent. Bundling of the BiSBr NWs occurs upon the addition of 1-octadecene as a co-solvent. The morphologies of the BiSBr NBs are easily tailored from sheaf-like structures to spherulite nanostructures by changing the solvent ratio. The optical bandgaps are modulated from 1.91 (BiSCl) and 1.88eV (BiSBr) to 1.53eV (BiSI) by changing the halide compositions. The optical bandgap of the ultrathin BiSBr NWs and NBs exhibits blueshift, whose origin is investigated through density functional theory-based first-principles calculations. Visible-light photodetectors are fabricated using BiSBr NWs and NBs via solution-based deposition followed by solid-state ligand exchanges. High photo-responsivities and external quantum efficiencies (EQE) are obtained for BiSBr NW and NB films even under strain, which offer a unique opportunity for the application of the novel BiSX NWs and NBs in flexible and environmentally friendly optoelectronic devices.

Evolution of CuO bundles of nanowires by room temperature surface oxidation of electroplated Cu for high-performing energy storage device

In the present work, copper oxide bundles of nanowires (CuO BNWs) were synthesized by room-temperature surface oxidation of an electroplated Cu layer in an alkaline bath. The time-dependent morphological evolution of CuO BNWs is systematically achieved by varying surface oxidation times. The CuO BNWs provide a high surface area (19.12 m2/g) and have shown excellent supercapacitive performance with a specific capacitance of 509 F/g at 1 A/g current density owing to fast electron transfer paths offered by BNWs. The all-solid-state hybrid supercapacitor device (SS//Cu//CuO-BNWs//KOH-PVA//rGO) demonstrates a specific capacitance of 77.3 F/g and energy density of 22.57 Wh/kg at a power density of 1.29 kW/kg.

Tapered cross-linked ZnO nanowire bundle arrays on three-dimensional graphene foam for highly sensitive electrochemical detection of levodopa.

It is crucial to accurately and rapidly monitor the levodopa (LD) concentration for accurate classification and treatment of dyskinesia in Parkinson's disease. In this paper, 3D graphene foam (GF) with a highly conductive network is obtained by chemical vapor deposition. 3D GF serves as the substrate for hydrothermal in situ growth of tapered cross-linked ZnO nanowire bundle arrays (ZnO NWBAs), enabling the development of a highly sensitive detection platform for LD. The formation mechanism of a tapered cross-linked ZnO nanowire bundle arrays on 3D GF is put forward. The integration of 3D GF and ZnO NWBAs can accelerate the electron transfer rate and increase the contact area with biomolecules, resulting in high electrochemical properties. The electrode composed of ZnO NWBAs on 3D GF exhibits significant sensitivity (1.66 µA·µM-1·cm-2) for LD detection in the concentration range0-60 µM. The electrode is able to rapidly and specifically determine LD in mixed AA or UA solution. The selectivity mechanism of the electrode is also explained by the bandgap model. Furthermore, the successful detection of LD in serum demonstrates the practicality of the electrode and its great potential for clinical application.

Synthesis of CuO nanosheets on Cu foil via one-step wet chemical process at different reaction temperatures and their photoelectrochemical performance

Cupric oxide (CuO) nanostructures were directly grown on copper substrate via a simple one step solution-immersion process. The films were formed by the direct oxidation of copper in aqueous solution containing sodium hydroxide (NaOH) and ammonium persulfate (NH4)2S2O8. The influence of the reaction temperature on the structural, morphological, optical and photoelectrochemical (PEC) properties of the formed copper compounds nanostructures was investigated. The XRD and Raman spectroscopy results revealed the formation of Cu(OH)2/CuO composite for the samples prepared at 3 and 25 °C, and pure CuO was obtained for the samples prepared at 45 and 55 °C. The SEM micrographs showed that the formed Cu(OH)2 and CuO present a nanowire bundles and nanosheet morphology, respectively. The increase of the reaction temperature enhanced the absorbance of the CuO samples in the entire visible region. According to the photoelectrochemical measurements, the increase of the reaction temperature resulted in an improvement of the PEC response. The CuO nanosheets synthesized at 55 °C presents the highest and the most stable PEC response. A reasonable mechanism describing the formation of nanostructured copper compounds at different reaction temperatures is discussed in this paper.

Bottom-Up Assembling Hierarchical Enamel-Like Bulk Materials with Excellent Optical and Mechanical Properties for Tooth Restoration.

Enamel has good optical and mechanical properties because of its multiscale hierarchical structure. Biomimetic construction of enamel-like 3D bulk materials at nano-, micro-, mesh- and macro-levels is a challenge. A novel facile, cost-effective, and easy large-scale bottom-up assembly strategy to align 1D hydroxyapatite (HA) nanowires bundles to 3D hierarchical enamel structure with the nanowires bundles layer-by-layer interweaving orientation, is reported. In the strategy, the surface of oleate templated ultralong HA nanowires with a large aspect ratio is functionalized with amphiphilic 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Furtherly, the MDP functionalized HA nanowire bundles are assembled layer-by-layer with oriented fibers in a single layer and cross-locked between layers at a certain angle at mesoscale and macroscale in the viscous bisphenol A-glycidyl methacrylate (Bis-GMA) ethanol solution by shear force induced by simple agitation and high-speed centrifugation. Finally, the excessive Bis-GMA and ethanol are removed, and (Bis-GMA)-(MDP-HA nanowire bundle) matrix is densely packed under hot pressing and polymerized to form bulk enamel-like materials. The composite has superior optical properties and comparable comprehensive mechanic performances through a combination of strength, hardness, toughness, and friction. This method may open new avenues for controlling the nanowires assembly to develop hierarchical nanomaterials with superior properties for many different applications.

Conjugating HA bundles with ZIF-8 for catalytic degradation of tetracycline and antibacterial capacity

The overused of antibiotics had led to major environmental issues and drug-resistant bacteria, which inevitably harmed the environment and public health. In this work, in order to obtain environmentally friendly bi-functional materials to combat with residual antibiotics and bacterial contamination, ZIF-8, a typical Zn based zeolitic imidazolate framework (ZnZIF) with excellent chemical stability, was conjugated to hydroxyapatite nanowire bundles (HAnBs) by a simple in-situ synthesis. The obtained ZnZIFs@HAnBs was characterized by SEM, EDS, XPS, FT-IR, XRD and BET. The effects of catalysts, catalyst dosage, TC initial concentration, PMS concentration and pH on TC degradation were investigated. Notably, ZnZIFs@HAnBs (94.0 %) exhibited excellent degradation effect of tetracycline (TC) within 15 min, which was 1.7 and 5.2 times than that of ZIF-8 (55.9 %) and HAnBs (18.1 %) under optimal conditions, respectively. Moreover, after recycling 10 times, the degradation rate still more than 86.8 %. The degradation mechanism was confirmed by free radical quenching experiment coupling with electron paramagnetic resonance (EPR), and the 1O2 and O2•- were the major reactive oxygen species in TC degradation. Furthermore, it presented excellent antibacterial activity (95.0 %) against E. coli and S. aureus, which was attributed to the synergistic effect of sustained release of Zn2+ and phosphate in ZnZIF@HAnBs. In summary, an eco-friendly bi-functional materials of HA nanowire bundles could be synthesized by simple strategy, and it could be applied in the fields of environmental remediation, as well as in treatment of antibiotic and bacterial pollution.

Biomimetically ordered ultralong hydroxyapatite nanowires-based hierarchical hydrogel scaffold with osteoimmunomodulatory and osteogenesis abilities for augmenting bone regeneration

Artificial construction of tissue engineering implants with bone-mimicking structure and osteogenic function is of great significance for bone regeneration, but it remains a formidable challenge. Herein, inspired by natural bone, a biomimetically hierarchical hydrogel scaffold with highly ordered arrangement and multi-layered concentric circular structure is constructed by a convenient free-injection method for osteoimmunomodulation and bone defect regeneration. Ultralong hydroxyapatite nanowires act as skeleton unit to assemble into the hierarchically ordered nanowire bundles and further hybridization with hyaluronic acid methacrylate and loading with layered double hydroxide nanosheets to form the stable biomimetic scaffold. The biomimetic scaffold exhibits anisotropic structure, high water content and porosity, mechanical robustness, and sustained release of bioactive ions. In particular, the excellent biocompatibility together with ordered topography and biochemical cue can guide recruitment and directional migration of stem cells, and effectively promote osteogenic differentiation and vascularization in vitro. Moreover, the biomimetic scaffold induces M2 phenotype polarization of macrophages, thus creating a favorable osteoimmune environment. The in vivo study proves that the biomimetic scaffold can attenuate inflammation, promote vascularized ossification, and further accelerate new bone formation. This study provides an innovative strategy to construct multifunctional anisotropic biomaterials for bone tissue engineering.

Influence of environmental conditions on the morphological evolution of bismuth oxide nanostructures via pulsed laser ablation in liquids

Bismuth oxide nanomaterials are increasingly recognized for their promising electronic and optical properties, particularly in electrochemical and biomedical applications. This study demonstrates that various bismuth oxide nanostructures can be synthesized through pulsed laser ablation in liquids (PLAL) by adjusting the concentration of dissolved gases from ambient conditions. Structural and compositional analyses were performed using x-ray diffraction, Raman spectroscopy, FTIR spectroscopy, and morphological investigations were conducted using atomic force microscopy and transmission electron microscopy. Our findings indicate that factors such as dissolved gases, laser fluence, and nanoparticle aging are crucial in determining the final structure and composition of the resulting nanomaterial. The phases observed ranged from spherical metallic bismuth nanoparticles to monoclinic bismuth oxide nanowire bundles, and orthorhombic bismuth carbonate oxide nanosheets. Dissolved gases are shown to influence not only the primary particles formed immediately after ablation, but also significantly impact the aging process of the colloid as well. Additionally, fluence plays an important role in the production of reactive oxygen species, thereby influencing the reactive pathways experienced by the ablated material and its subsequent formation into nanostructures. A notable result, emphasizing the significance of factors such as liquid environment and fluence when performing PLAL on reactive targets like bismuth, is seen in high fluence (20 J/cm2) samples under ambient conditions. These samples initially display an amalgamation of α-Bi2O3 nanowire bundles and carbonate nanosheets, which upon aging, transition to predominantly bismuth oxide nanowire bundles. This contrasts with samples produced in a saturated CO2 environment where bismuth carbonate nanosheets remain highly stable in the colloid.

Extraction of Ag3Sn nanowires bundle and its electrochemical characteristics

The Ag3Sn nanowires (NWs) bundle embedded in the Sn-3.5Ag eutectic alloy bar directionally solidified was extracted by utilizing electrochemical selective corrosion, during which the Sn-base was dissolved and the Ag3Sn fibrous phase was remained. The diameter of Ag3Sn NWs decreases with the increasing of directional solidification rate, and their length increases with the corrosion duration. Utilizing the electrochemical alternative current (AC) impedance method and the cyclic voltammetry (CV), the interfacial impedance and the charge storage capacity of electrodes with Ag3Sn NWs bundle were tested in 0.9 % NaCl aqueous solution. The measuring results indicated that the lowest interfacial impedance appeared at the average length of nanowires with 8 µm, whereas the charge storage capacity was increased constantly with the length of Ag3Sn NWs. These electrochemical characteristics make the Ag3Sn NWs bundle electrodes possible to be applied as the electrophysiological electrode. A series of trial EEG (electroencephalogram) tests showed that the EEG signals of Ag3Sn NWs dry electrodes had a higher correlation to that of Ag/AgCl wet electrodes.

Iron Selenide Nanowire Bundles for Microwave Communication Technology

Herein, stacked layers of FeSe2 deposited onto ytterbium substrates using the thermal evaporation technique under a vacuum pressure of 10−5 mbar are observed to form nanowire bundles (NBs). Structural investigations on these NBs have shown the preferred growth of orthorhombic FeSe2 in addition to hexagonal ytterbium selenide as a minor phase in the structure of FeSe2. Impedance spectroscopy analyses conducted in the frequency domain of 0.01–1.80 GHz show that FeSe2 stacks can exhibit a negative capacitance effect and bandstop filter characteristics. For these bandstop filters, the refection coefficient (), the voltage standing wave ratios (), and the return loss () spectra display optimum values at a notch frequency of 0.87 GHz. In addition, computational analysis using Lorentz oscillator model has shown that the negativity of the capacitance is dominated by two oscillators centered at 0.08 and 1.25 GHz. On the other hand, the insertion of aluminum nanosheets between the stacked layers of FeSe2 has been observed to decrease the negativity of the capacitance, increase the values of and , and bring the closer to ideality. FeSe2 nanowire bundles resulting from FeSe2 stacks comprising Al nanosheets are considered suitable for microwave communication technology.

Synthesis of Zn-Co-S nanowire bundle type aerogel electrodes for asymmetric supercapacitors

Synthesis of Zn-Co-S nanowire bundle type aerogel electrodes for asymmetric supercapacitors

Oxide-Derived Copper Nanowire Bundles for Efficient CO2 Reduction to Multi-Carbon Products

Cu-based catalysts for efficient C2+ production from CO2 electrocatalytic reduction reaction (CO2ERR) exhibit significant promise, but still suffer from ambiguous mechanisms due to the intrinsic structure instability during electroreduction. Herein, we report an oxide-derived copper nanowire bundle (OD-Cu NWB) for efficient CO2ERR to C2+ products. OD-Cu NWBs with a well-preserved nanowire bundle morphology lead to promoted multi-carbon production compared to commercial copper powders. The formation of OD-Cu NWBs shows a great dependence on the precipitation/calcination temperatures and per-reduction potentials, which further influence the ultimate CO2ERR performance correspondingly. The optimized preparation parameters for the formation of a well-ordered nanowire bundle morphology are found, leading to a preferred C2+ production ability. Besides the nanowire bundle morphology, the oxide-derived Cu essence of OD-Cu NWBs with stabilized Cu+ species from per-reduction also promotes the CO2ERR activity and facilitates the C-C coupling of key intermediates for C2+ production. This work provides a facile strategy and inspiration for CO2ERR catalyst developments targeting high-valued multi-carbon products.

Bonding-Driven Crystallization of Dimensionally Resolved Nanostructures Based on Quasi-1D Van Der Waals Building Blocks

The discovery of complex phenomena and strongly correlated behavior in the solid state has incessantly relied upon the creation of stable low-dimensional lattices approaching the atomic limit. Whereas 2D van der Waals (vdW) materials with atomic scale thicknesses have gained widespread interest, very little has been known about the chemistry and physics of their more confined 1D counterparts in the solid state. In these length scales and dimensionalities, unique physical properties arising from finite size effects such as ballistic electrical transport, size-dependent optical resonance modes, long carrier lifetimes, and exotic higher-order topological states become realizable. To this end, I will present the recent efforts in my group towards elucidating the chemical bonding interactions which define the structure and nanoscale dimensionality of structures derived from lattices which are comprised of 1D chains with sub-nm diameters that are held together by weak vdW interactions. By gaining anisotropy-driven control over these interactions via bottom-up chemical vapor growth, we demonstrate the creation of dimensionally-resolved nanostructures with various thicknesses ranging from 1D nanowire bundles to quasi-2D nanoribbons and nanosheets, all based on a the same 1D vdW lattice motif. Extensive electron diffraction and atomic-resolution microscopy of these resulting nanostructures reveal the strong dependence of the size and dimensionality of the 1D and quasi-2D nanostructures on anisotropic inter-chain vdW bonding interactions, precursor ratios, and growth temperatures. Using these results, we propose a crystallization mechanism defined by the competition between covalent and vdW bonding interactions and epitaxy. As physical properties directly correlate to the structure, dimensionality, and size in the solid state, I will also talk about how the unique topographies of resulting freestanding nanostructures dictate their electronic properties. I will describe how the synthetic control over the structural attributes led to our discovery of emergent properties such as the elusive indirect-to-direct band gap transition and higher-order topological states in 1D vdW nanostructures. Through these efforts, we define for the first time the anisotropy-driven growth of these emergent 1D vdW-derived nanostructures and how nanoscale morphologies in these nanostructures dictate their electronic structures. Altogether, this precise control over crystalline and electronic structure poises these emergent low-dimensional solids as building blocks towards programmable electrocatalysts, densified electronic and quantum devices in sensing, photonic, energy storage and conversion, and spintronic technologies.

High Mechanical Energy Storage Capacity of Ultranarrow Carbon Nanowires Bundles by Machine Learning Driving Predictions

Energy storage and renewable energy sources are critical for addressing the growing global energy demand and reducing the negative environmental impacts of fossil fuels. Carbon nanomaterials are extensively explored as high reliable, reusable, and high‐density mechanical energy storage materials. In this context, machine learning techniques, specifically machine learning potentials (MLPs), are employed to explore the elastic properties of 1D carbon nanowires (CNWs) as a promising candidate for mechanical energy storage applications. The study focuses on the elastic energy storage properties of these CNWs, utilizing MLPs trained with data from first‐principles molecular dynamics simulations. It is found that these materials exhibit an exceptionally high tensile elastic energy storage capacity, with a maximum storage density ranging from 2262 to 2680 kJ kg−1. Furthermore, it is discovered that some CNWs exhibit a superior torsional energy storage capacity compared to their tensile energy storage capacity. Overall, this research demonstrates the effectiveness of machine learning‐based computational approaches in accelerating the exploration and optimization of novel materials. It also highlights the potential of CNWs as promising candidates for future energy storage applications.

Microwave-Assisted Metal-Organic Frameworks Derived Synthesis of Zn2GeO4 Nanowire Bundles for Lithium-Ion Batteries.

Germanium-based multi-metallic-oxide materials have advantages of low activation energy, tunable output voltage, and high theoretical capacity. However, they also exhibit unsatisfactory electronic conductivity, sluggish cation kinetics, and severe volume change, resulting in inferior long-cycle stability and rate performance in lithium-ion batteries (LIBs). To solve these problems, we synthesize metal-organic frameworks derived from rice-like Zn2GeO4 nanowire bundles as the anode of LIBs via a microwave-assisted hydrothermal method, minimizing the particle size and enlarging the cation's transmission channels, as well as, enhancing the electronic conductivity of the materials. The obtained Zn2GeO4 anode exhibits superior electrochemical performance. A high initial charge capacity of 730 mAhg-1 is obtained and maintained at 661 mAhg-1 after 500 cycles at 100 mA g-1 with a small capacity degradation ratio of ~0.02% for each cycle. Moreover, Zn2GeO4 exhibits a good rate performance, delivering a high capacity of 503 mA h g-1 at 5000 mA g-1. The good electrochemical performance of the rice-like Zn2GeO4 electrode can be attributed to its unique wire-bundle structure, the buffering effect of the bimetallic reaction at different potentials, good electrical conductivity, and fast kinetic rate.

Plasmonic Molybdenum Dioxide Ultrathin Nanowire Bundles for Highly Sensitive, Stable, and Reproducible Surface-Enhanced Raman Spectroscopy

In surface-enhanced Raman spectroscopy (SERS) detection, it is important to improve the sensitivity, stability, and reproducibility of semiconductor surface-enhanced Raman scattering (SERS) substrates. Here, a simple chemical method was used to synthesize molybdenum dioxide ultrathin nanowire bundles. The ultrathin nanowire bundles of molybdenum dioxide demonstrate distinct and robust surface plasmon resonance (SPR) effects within the visible light range. As a low-cost SERS substrate, the plasmonic molybdenum dioxide nanowire beams exhibit a Raman enhancement factor of 2.9 × 107 and a minimum detection limit of 1.0 × 10–11 mol L–1 for Rhodamine 6G. In addition, these SERS substrates based on molybdenum dioxide ultrathin nanowires exhibit good chemical stability and can resist corrosion by strong acids and bases over time. The molybdenum dioxide ultrathin nanowire bundles have a high potential to become an ideal metal-oxide-based SERS substrate material.

Protonic conductivity in metalloprotein nanowires

Protonic devices with a bundle of metalloprotein nanowires (MPNs) and palladium hydride (PdHx) protodes were fabricated.I–Vmeasurements with and without H2show that the MPN bundles lower the device resistance by a factor of 4–5 under H2.

Skin breathable and stretchable electrode based on square-shaped AgNW bundle mesh with wavy bridges

This work presents a skin-breathable and biaxially stretchable electrode consisting of a micropatterned silver nanowire bundle with a square mesh and wavy bridges on a hole-patterned ultrathin elastomer matrix, fabricated by solution-based processes.

CoO, Cu, and Ag Nanoparticles on Silicon Nanowires with Photocatalytic Activity for the Degradation of Dyes

Photocatalytic semiconductors require maintaining stability and pursuing higher efficiencies. The studied systems were silicon nanowires (SiNWs), silicon nanowires with cobalt oxide nanoparticles (SiNWs-CoONPs), and silicon nanowires with copper nanoparticles (SiNWs-CuNPs). SiNWs were synthesized by metal-assisted chemical etching (MACE) from silicon wafers keeping the remaining silver nanoparticles for all three sample types. The nanowires were about 23–30 µm in length. CoONPs and CuNPs were deposited on SiNWs by the autocatalytic reduction processes (electroless). There were many factors in the process that affect the resulting structures and degradation efficiencies. This work shows the degradation of methyl orange (MO) together with the chemisorption of methylene blue (MB), and rhodamine 6G (Rh6G) by direct illumination with visible radiation. The MO degradation kinetics were in the sequence SiNWs-CuNPs (88.9%) > SiNWs (85.3%) > SiNWs-CoONPs (49.3%), with the SiNWs-CuNPs having slightly faster kinetics. However, SiNWs-CoONPs have slow degradation kinetics. The chemisorptions of MB and Rh6G were SiNWs-CuNPs (87.2%; 86.88%) > SiNWs (86%; 87%) > SiNWs-CoONPs (17.3%; 12%), showing dye desorptions together with lower chemisorption capacities. This work shows iridescence in optical microscopy images by the visible light interference caused by the spaces between the nanowire bundles.

Effect of Au film mask on antiwetting and antireflection properties of nanostructural polymer by plasma nanotexturing

Capacitively coupled radiofrequency plasma nanotexturing assisted by an Au film mask is carried out to fabricate the fluorocarbon-film decorated nanowires bundles from the semicrystalline polyethylene (PE) and amorphous PolyMethyl methacrylate (PMMA) subatrates. The spacing distance and height of the nanowires in a bundle on the PE and PMMA substrates are adjusted by the thickness of Au film mask. The complete rebound phenomenon occurs when the droplets impact with a high speed on the nanowire bundles. The nanowire bundles exhibit an improved superhydrophobicity. The narrow spacing distance between the nanowires is beneficial to the antiwetting of superhydrophobic surface. The low reflectivity of the nanowire bundles is also obtained with an incident light wavelength from 400 to 2000 nm. The antireflection property of the nanowire bundles is caused by the high height of nanowires in a bundle. The nanowire bundles on the PE and PMMA substrates prepared by the plasma nanotexturing assisted by the Au film mask have the excellent antiwetting and antireflection properties.